Quad flat non-leaded package and manufacturing method thereof

ABSTRACT

A quad flat non-leaded package including a first patterned conductive layer, a second patterned conductive layer, a chip, bonding wires and a molding compound is provided. The first patterned conductive layer defines a first space, and the second patterned conductive layer defines a second space, wherein the first space overlaps the second space and a part of the second patterned conductive layer surrounding the second space. The chip is disposed on the second patterned conductive layer. The bonding wires are connected between the chip and the second patterned conductive layer. The molding compound encapsulates the second patterned conductive layers, the chip and the bonding wires. In addition, a method of manufacturing a quad flat non-leaded package is also provided.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan applicationserial no. 97147881, filed on Dec. 9, 2008. The entirety of theabove-mentioned patent application is hereby incorporated by referenceherein and made a part of this specification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a quad flat package (QFP) andmanufacturing method thereof. More particularly, the present inventionrelates to a quad flat non-leaded (QFN) package and manufacturing methodthereof.

2. Description of Related Art

Production of integrated circuits (IC) includes IC design, IC processand IC package. The package of IC prevents the chip from effects ofexternal temperature, humidity and contamination, and provides medium ofelectric connection between the chip and external circuits.

Chip package are categorized in various package types, wherein the quadflat non-leaded package belonging to the category of quad flat packageand characterized by short signal transmission path and rapid signaltransmission speed is suitable for high frequency chip package and thusbeing a main stream of low pin count package.

In the manufacturing method of quad flat non-leaded package, chips aredisposed on a leadframe. Then, the chips are electrically connected tothe leadframe via bonding wires. Next, patterned conductive layers, thebonding wires and the chip are encapsulated by a molding compound.Thereafter, the aforementioned structure is singularized to form aplurality of quad flat non-leaded packages.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a quad flat non-leadedpackage capable of reducing package thickness.

The present invention is also directed to a manufacturing method of aquad flat non-leaded package with low manufacturing cost.

As embodied and broadly described herein, the present invention providesa quad flat non-leaded package, comprising: a first patterned conductivelayer defining a first space having a pattern complementary to a patternof the first patterned conductive layer; a second patterned conductivelayer defining a second space having a pattern complementary to apattern of the second patterned conductive layer, wherein the firstspace overlaps the second space and a part of the second patternedconductive layer surrounding the second space; a chip disposed on thesecond patterned conductive layer, wherein the second patternedconductive layer is located between the chip and the first patternedconductive layer; a plurality of bonding wires connected between thechip and the second patterned conductive layer; and a molding compoundencapsulating the second patterned conductive layer, the chip and thebonding wires.

The present invention also provides a method of manufacturing a quadflat non-leaded package. The method comprises: providing a sacrificedlayer, two release films and two metal layers; stacking the sacrificedlayer between the two release films and stacking the two release filmsand the sacrificed layer between the two metal layers, wherein eachrelease film exposes a part of the sacrificed layer, and each metallayer covers one of the release films and the part of the sacrificedlayer exposed by the release film; forming a first mask layer on eachmetal layer, wherein each first mask layer exposes a part of thecorresponding metal layer; forming a first patterned conductive layer onthe part of the metal layer exposed by each first mask layer; removingeach first mask layer and each first patterned conductive layer exposesa part of the corresponding metal layer; forming a dielectric layer onthe part of the corresponding metal layer exposed by each firstpatterned conductive layer; cutting the dielectric layers, the metallayers, the release films and the sacrificed layer; removing thesacrificed layer and the release films after cutting the dielectriclayers, the metal layers, the release films and the sacrificed layer;removing the metal layers after removing the sacrificed layer and therelease films; disposing at least one chip on each first patternedconductive layer; and forming a plurality of bonding wires toelectrically connect each chip to the corresponding first patternedconductive layer.

The present invention provides further another method of manufacturing aquad flat non-leaded package. The method comprises: providing asacrificed layer, two release films and two metal layers; stacking thesacrificed layer between the two release films and stacking the tworelease films and the sacrificed layer between the two metal layers,wherein each release film exposes a part of the sacrificed layer, andeach metal layer covers one of the release films and the part of thesacrificed layer exposed by the release film; forming a first mask layeron each metal layer, wherein each first mask layer exposes a part of thecorresponding metal layer; forming a first patterned conductive layer onthe part of the metal layer exposed by each first mask layer; cuttingthe dielectric layers, the metal layers, the release films and thesacrificed layer; removing the sacrificed layer and the release filmsafter cutting the dielectric layers, the metal layers, the release filmsand the sacrificed layer; removing the metal layers after removing thesacrificed layer and the release films; disposing at least one chip oneach first patterned conductive layer; forming a plurality of bondingwires to electrically connect each chip to the corresponding firstpatterned conductive layer; forming a plurality of molding compounds,wherein each molding compound encapsulates the corresponding chip andthe bonding wires connected to the chip; and removing the first masklayers.

The present invention disposes release films on a part area of thesacrificed layer in manufacturing process of the quad flat non-leadedpackage, such that the metal layers can be adhered to the remained areaof the sacrificed layer exposed by the release films. Then, the remainedarea of the sacrificed layer exposed by the release films is removed andthe metal layers can separate from the sacrificed layer as the releasefilms peeling from the sacrificed layer.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

FIGS. 1A to 1H are sectional views illustrating a method ofmanufacturing a quad flat non-leaded package according to an embodimentof the present invention.

FIG. 2 is a sectional view showing a method of manufacturing a quad flatnon-leaded package according to another embodiment of the presentinvention.

FIG. 3 is a sectional view showing a method of manufacturing a quad flatnon-leaded package according to another embodiment of the presentinvention.

FIGS. 4A to 4E are sectional views showing a method of manufacturing aquad flat non-leaded package according to further another embodiment ofthe present invention.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numbers areused in the drawings and the description to refer to the same or likeparts.

FIGS. 1A to 1H are sectional views illustrating a method ofmanufacturing a quad flat non-leaded package according to an embodimentof the present invention. First, referring to FIG. 1A, a sacrificedlayer 110, two release films 120 and two metal layers 130 are provided.Then, the sacrificed layer 110 is stacked between the two release films120, and the two release films 120 and the sacrificed layer 110 arestacked between the two metal layers 130. Each release film 120 isembedded into the sacrificed layer 110 and exposes a part of thesacrificed layer 110. Each metal layer 130 covers the correspondingrelease film 120 and the part of the sacrificed layer 110 exposed by therelease film 120. Then, a first mask layer 140 is formed on each metallayer 130, wherein each first mask layer 140 exposes a part of itscorresponding metal layer 130.

It should be noted that the release films 120 are not completely coverthe sacrificed layer 110, such that the area A of the sacrificed layer110 exposed by the release films 120 can be adhered with the metallayers 130.

Referring to FIG. 1B, a first patterned conductive layer 150 is formedon the part of each metal layer 130 exposed by the corresponding firstmask layer 140. In addition, in this embodiment, further a firstoxidation prevention layer 160 can be formed on the part of each metallayer 130 exposed by the corresponding first mask layer 140 before thefirst patterned conductive layers 150 are formed.

Referring to FIG. 1C, the first mask layers 140 are removed such thateach first patterned conductive layer 150 exposes a part of thecorresponding metal layer 130. Then, referring to FIG. 1D, a dielectriclayer 170 is formed on the part of each metal layer 130 exposed by itscorresponding first patterned conductive layer 150. Referring to FIG.1E, a second mask layer 140′ is formed on each dielectric layer 170,wherein each second mask layer 140′ exposes the corresponding firstpatterned conductive layer 150 and a part of the dielectric layer 170surrounding the first patterned conductive layer 150. Then, a secondpatterned conductive layer 150′ is formed on the corresponding firstpatterned conductive layer 150 and the part of the dielectric layer 170surrounding the first patterned conductive layer 150. In thisembodiment, a second oxidation prevention layer 160′ can further beformed on each second patterned conductive layer 150′.

Referring to FIGS. 1F and 1G, the second mask layers 140′ are removed.Then, the dielectric layers 170, the metal layers 130, the release films120 and the sacrificed layer 110 are cut to remove the area A of thesacrificed layer 110 exposed by the release films 120. Then, thesacrificed layer 110 and the release films 120 are removed.

There exists temporary bonding force between the metal layers 130 andthe release films 120 and the method of separating the metal layers 130from the release films 120 should eliminate the bonding forcetherebetween. The metal layers 130 and the release films 120 can beseparated by chemical or physical manners. In this embodiment, themethod of removing the sacrificed layer 110 and the release films 120comprises peeling the metal layers 130 from their corresponding releasefilms 120 in a physical manner.

It should be noted that the above step of removing the area A of thesacrificed layer 110 exposed by the release films 120 brings the metallayers 130 isolated from the sacrificed layer 110 by their correspondingrelease films 120, such that the metal layers 130 can be peeled fromtheir corresponding release films 120 easily.

Referring to FIG. 1H, a chip 180 is disposed on the second patternedconductive layer 150′. Bonding wires 190 are formed to electricallyconnect the chip 180 to the patterned conductive layer 150 and thesecond patterned conductive layer 150′. A molding compound M is formedto encapsulate the chip 180 and the bonding wires 190. Then, the metallayer 130 is removed to form a quad flat non-leaded package 100. In thisembodiment, the metal layer 130 is for example removed by etching.

It should be noted that in another embodiment not shown, plural andcorresponding chips, bonding wires and molding compounds are provided toobtain a plurality of quad flat non-leaded packages after a singulationprocess.

Referring to FIG. 1H, the quad flat non-leaded package 100 of thepresent embodiment comprises a first patterned conductive layer 150, asecond patterned conductive layer 150′, a chip 180, a plurality ofbonding wires 190 and a molding compound M. The first patternedconductive layer 150 defines a first space S1 having a patterncomplementary to that of the first patterned conductive layer 150. Thesecond patterned conductive layer 150′ defines a second space S2 havinga pattern complementary to that if the second patterned conductive layer150′. The first space S1 overlaps the second space S2 and a part of thesecond patterned conductive layer 150′ surrounding the second space S2.

The chip 180 is disposed on the second patterned conductive layer 150′,wherein the second patterned conductive layer 150′ is located betweenthe chip 180 and the first patterned conductive layer 150. The bondingwire 190 connects between the chip 180 and the second patternedconductive layer 150′. The molding compound M encapsulates the secondpatterned conductive layer 150′, the chip 180 and the bonding wires 190.

In addition, the quad flat non-leaded package 100 further comprises adielectric layer 170, a first oxidation prevention layer 160 and asecond oxidation prevention layer 160′. The dielectric layer 170 isfilled into the first space S1 and overlaps the second space S2 and thepart of the second patterned conductive layer 150′ surrounding thesecond space S2. The first oxidation prevention layer 160 is disposed onthe first patterned conductive layer 150, wherein the first patternedconductive layer 150 is located between the first oxidation preventionlayer 160 and the second patterned conductive layer 150′. The secondoxidation prevention layer 160′ is disposed on the second patternedconductive layer 150′, wherein the second patterned conductive layer150′ is located between the second oxidation prevention layer 160′ andthe first patterned conductive layer 150.

A method of manufacturing a quad flat non-leaded package according toanother embodiment of the present invention is presented in thefollowing. FIG. 2 is a sectional view showing a method of manufacturinga quad flat non-leaded package according to another embodiment of thepresent invention. Former process of the manufacturing method of thisembodiment is similar to the steps illustrated in FIG. 1A to 1F, andthus the detailed descriptions are not repeated herein.

Referring to FIGS. 1F and 2, a chip 180 is disposed on each secondpatterned conductive layer 150′. Bonding wires 190 are formed toelectrically connect each chip 180 to its corresponding first patternedconductive layer 150 and second patterned conductive layer 150. Then,two molding compounds M′ are formed to encapsulate the chips 180 and thebonding wires 190 connected to the chips 180.

Next, the molding compound M′, the dielectric layers 170, the metallayers 130, the release films 120 and the sacrificed layer 110 are cutto remove the area A of the sacrificed layer 110 exposed by the releasefilms 120. Then, the sacrificed layer 110 and the release films 120 areremoved to obtain two quad flat non-leaded packages 100 as shown in FIG.1H.

A method of manufacturing a quad flat non-leaded package according tofurther another embodiment of the present invention is presented in thefollowing. FIG. 3 is a sectional view showing a method of manufacturinga quad flat non-leaded package according to another embodiment of thepresent invention. Former process of the manufacturing method of thisembodiment is similar to the steps illustrated in FIG. 1A to 1D, andthus the detailed descriptions are not repeated herein.

Referring to FIGS. 1D and 3, a conductive layer 150 a is formed on eachdielectric layer 170, wherein each conductive layer 150 a overlaps thecorresponding dielectric layer 170 and the first patterned conductivelayer 150. Then, a second mask layer 140′ is formed on each conductivelayer 150 a, wherein each second mask layer 140′ exposes a part of thecorresponding conductive layer 150 a. A second oxidation preventionlayer 160′ is formed on the part of each conductive layer 150 a exposedby the corresponding second mask layer 140′.

Then, each second mask layers 140′ is removed and each conductive layer150 a is patterned to form a second patterned conductive layer 150′ toobtain the structure as shown in FIG. 1F. The following process of themanufacturing method of this embodiment is similar to the stepillustrated in FIG. 1F to 1H, and thus the detailed descriptions are notrepeated herein.

A method of manufacturing a quad flat non-leaded package according tofurther another embodiment of the present invention is presented in thefollowing. FIGS. 4A to 4E are sectional views showing a method ofmanufacturing a quad flat non-leaded package according to furtheranother embodiment of the present invention. Former process of themanufacturing method of this embodiment is similar to the stepsillustrated in FIG. 1A to 1B, and thus the detailed descriptions are notrepeated herein.

Referring to FIGS. 1B and 4A, a second mask layer 140′ is formed on eachfirst mask layer 140, wherein each second mask layer 140′ exposes thecorresponding first patterned conductive layer 150 and a part of thefirst mask layer 140 surrounding the first patterned conductive layer150. Then, a second patterned conductive layer 150′ is formed on thefirst patterned conductive layer 150 and the part of the first masklayer 140 surrounding the first patterned conductive layer 150 exposedby each second mask layer 140′. In this embodiment, a second oxidationprevention layer 160′ can be further formed on each second patternedconductive layer 150′.

Referring to FIGS. 4B and 4C, each second mask layer 140′ is removed.Then, the first mask layers 140, the metal layers 130, the release films120 and the sacrificed layer 110 are cut to remove the area A of thesacrificed layer 110 exposed by the release films 120. Next, thesacrificed layer 110 and the release films 120 are removed.

Referring to FIG. 4D, a chip 180 is disposed on the first patternedconductive layer 150. Bonding wires 190 are formed to electricallyconnect the chip 180 to the first patterned conductive layer 150. Then,a molding compound M is formed to encapsulate the chip 180 and thebonding wires 190 connected to the chip 180. Next, referring to FIG. 4E,the metal layer 130 and the first mask layer 140 are removed in sequenceto obtain a quad flat non-leaded package 100′.

Referring to FIG. 4E, comparing to the quad flat non-leaded package 100of FIG. 1H, the quad flat non-leaded package 100′ of the embodiment doesnot have the dielectric layer 170, and a part of the second patternedconductive layer 150′ surrounding the second space S2 is exposed.

The present invention disposes release films on a part area of thesacrificed layer in manufacturing process of the quad flat non-leadedpackage, such that the metal layers can be adhered to the remained areaof the sacrificed layer exposed by the release films. Then, the remainedarea of the sacrificed layer exposed by the release films is removed bycutting and the metal layers can directly separate from the sacrificedlayer by peeling the metal layers from the release films, so that theefficiency of the manufacturing process can be improved. In addition,the quad flat non-leaded package of the present invention has lowerpackage thickness.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims and their equivalents.

1. A method of manufacturing a quad flat non-leaded package, the methodcomprising steps of: providing a sacrificial layer, two release filmsand two metal layers; stacking the sacrificial layer between the tworelease films and stacking the two release films and the sacrificiallayer between the two metal layers, wherein each release film exposes apart of the sacrificial layer, and each metal layer covers one of therelease films and the part of the sacrificial layer exposed by therelease film; forming a first mask layer on each metal layer, whereineach first mask layer exposes a part of the corresponding metal layer;forming a first patterned conductive layer on the part of the metallayer exposed by each first mask layer; removing each first mask layerand each first patterned conductive layer exposes a part of thecorresponding metal layer; forming a dielectric layer on the part ofeach corresponding metal layer exposed by each first patternedconductive layer; cutting the dielectric layers, the metal layers, therelease films and the sacrificed layer; removing the sacrificial layerand the release films after cutting the dielectric layers, the metallayers, the release films and the sacrificial layer; removing the metallayers after removing the sacrificial layer and the release films;disposing at least one chip on each first patterned conductive layer;and forming a plurality of bonding wires to electrically connect eachchip to the corresponding first patterned conductive layer.
 2. Themethod according to claim 1, wherein the release films are embedded intothe sacrificial layer.
 3. The method according to claim 1, furthercomprising: forming a first oxidation prevention layer on the part ofthe metal layer exposed by the corresponding first mask layer afterforming the first mask layer on the corresponding metal layer and beforeforming the first patterned conductive layer on the part of the metalexposed by the corresponding first mask layer.
 4. The method accordingto claim 1, further comprising: forming a second mask layer on eachdielectric layer before disposing the at least one chip at thecorresponding first patterned conductive layer, wherein each second masklayer exposes the corresponding first patterned conductive layer and apart of the dielectric layer surrounding the first patterned conductivelayer; forming a second patterned conductive layer on each firstpatterned conductive layer and the part of the dielectric layersurrounding the first patterned conductive layer exposed by thecorresponding second mask layer; and removing each second mask layer. 5.The method according to claim 4, wherein disposing the at least one chipon the corresponding first patterned conductive layer comprises:disposing the at least one chip on the corresponding second patternedconductive layer to make the chip being disposed on the correspondingfirst patterned conductive layer.
 6. The method according to claim 4,further comprising: forming a second oxidation prevention layer on eachsecond patterned conductive layer before disposing the at least one chipon the corresponding first patterned conductive layer.
 7. The methodaccording to claim 1, further comprising: forming a conductive layer oneach dielectric layer before disposing the at least one chip on thecorresponding first patterned conductive layer, wherein each conductivelayer covers the corresponding dielectric layer and the correspondingfirst patterned conductive layer; and patterning each conductive layerto form a second patterned conductive layer, wherein each secondpatterned conductive layer covers the corresponding first patternedconductive layer and a part of the dielectric layer surrounding thefirst patterned conductive layer.
 8. The method according to claim 7,wherein disposing the at least one chip on the corresponding firstpatterned conductive layer comprises: disposing the at least one chip onthe corresponding second patterned conductive layer to make the chipbeing disposed on the corresponding first patterned conductive layer. 9.The method according to claim 7, further comprising: forming a secondmask layer on each conductive layer before the conductive layer ispatterned to the second patterned conductive layer, wherein each secondmask layer exposes a part of the corresponding conductive layer; forminga second oxidation prevention layer on the part of each conductive layerexposed by the corresponding second mask layer; and removing each secondmask layer.
 10. The method according to claim 1, further comprising:forming a plurality of molding compounds after forming the bondingwires, wherein each molding compound encapsulates the corresponding chipand the bonding wires connected to the corresponding chip.
 11. Themethod according to claim 1, further comprising: forming two moldingcompounds after forming the bonding wires, wherein each molding compoundencapsulates the at least one chip on the corresponding first patternedconductive layer and the bonding wires connected to the at least onechip; and cutting each molding compound.
 12. A method of manufacturing aquad flat non-leaded package, the method comprising steps of: providinga sacrificial layer, two release films and two metal layers; stackingthe sacrificial layer between the two release films and stacking the tworelease films and the sacrificial layer between the two metal layers,wherein each release film exposes a part of the sacrificial layer, andeach metal layer covers one of the release films and the part of thesacrificial layer exposed by the release film; forming a first masklayer on each metal layer, wherein each first mask layer exposes a partof the corresponding metal layer; forming a first patterned conductivelayer on the part of the metal layer exposed by each first mask layer;cutting dielectric layers, the metal layers, the release films and thesacrificial layer; removing the sacrificial layer and the release filmsafter cutting the dielectric layers, the metal layers, the release filmsand the sacrificial layer; removing the metal layers after removing thesacrificial layer and the release films; disposing at least one chip oneach first patterned conductive layer; forming a plurality of bondingwires to electrically connect each chip to the corresponding firstpatterned conductive layer; forming a plurality of molding compounds,wherein each molding compound encapsulates the corresponding chip andthe bonding wires connected to the corresponding chip; and removing thefirst mask layers.
 13. The method according to claim 12, furthercomprising: forming a first oxidation prevention layer on the part ofthe metal layer exposed by the corresponding first mask layer afterforming the first mask layer on the corresponding metal layer and beforeforming the first patterned conductive layer on the part of the metalexposed by the corresponding first mask layer.
 14. The method accordingto claim 12, further comprising: forming a second mask layer on eachfirst mask layer before disposing the at least one chip at thecorresponding first patterned conductive layer, wherein each second masklayer exposes the corresponding first patterned conductive layer and apart of the first mask layer surrounding the first patterned conductivelayer: forming a second patterned conductive layer on each firstpatterned conductive layer and the part of the first mask layersurrounding the first patterned conductive layer exposed by thecorresponding second mask layer; and removing each second mask layer.15. The method according to claim 14, wherein disposing the at least onechip on the corresponding first patterned conductive layer comprises:disposing the at least one chip on the corresponding second patternedconductive layer to make the corresponding chip being disposed on thecorresponding first patterned conductive layer.
 16. The method accordingto claim 14, further comprising: forming a second oxidation preventionlayer on each second patterned conductive layer before disposing the atleast one chip on the corresponding first patterned conductive layer.